vcgencmd display not turning back on

Question

I am having an issue with vcgencmd display_power 1. This is a code chunk that Iḿ using to test the logic.

#include <wiringPi.h>
#include <stdio.h>
#include <stdlib.h>
#include <stdint.h>
#include <unistd.h>

int main(void)
{
printf("Ẅaiting 15 seconds");
delay(5000);
printf("Putting monitor to sleep");
system("vcgencmd display_power 0");
delay(10000);
printf("Waking monitor up");
system("vcgencmd display-power 1");
return 0;
}

The way Iḿ understanding things this program should wait 5 seconds, turn the display off then wait another 10 seconds and turn it back on.

I know that this is something that anyone would ever logically do. I am having a difficult time with a project and triggering the screen to wake back up. I have narrowed the issue down to just display_power 1 not turning the screen back on.

Answer 1

You have a typo in your code. This line...

system("vcgencmd display-power 1");

...Should have an underscore: display_power instead of a dash display-power.

That should fix it for you. Good luck!